In construction, there is a need to tether construction workers to the structure being constructed, so that if the worker falls, the fall is shortened so that the worker is not injured or killed. Typically, the worker wears a harness, and the harness is removably connected, or attached, to a lanyard. Essentially, a lanyard is a flexible tensile member such as a rope, cable, or web that has attachment hardware, typically a carabiner, at each end. Typically, at one end of the lanyard, the lanyard is coupled to an “anchor point” on the structure, and at the other end of the lanyard, the lanyard is coupled to the harness.
To couple the lanyard, specifically the carabiner at the end thereof, to either the harness or the anchor point requires yet another piece of attachment hardware known as a “D-ring.” A typical D-ring 2 is shown in FIG. 1, and FIG. 2 shows a lanyard 4 attached to the D-ring 2 via a carabiner 6.
Referring to FIG. 1, the D-ring 2 generally has two closed apertures A1 and A2. The larger aperture A1 is for receiving the carabiner. The smaller aperture A2 is for attaching to a structure. For example, FIG. 3 shows the D-ring 2 attached to a harness 8 formed of webbing 7. A loop of the webbing extends through the aperture A2, to connect the D-ring to the harness.
FIG. 4 shows another example, where the D-ring 2 used as an anchor point attached to a wall 9 of the structure. In this example, a (typically) metal loop structure or strap 5 extends through the aperture A2, the strap being bolted to the wall.
The D-ring must be strong enough to meet ANSI standard Z359.1 for the given application, which requires at least the capacity to withstand 5000 pounds force, either tensile or shear, applied to the D-ring through the lanyard 4, in an operating environment such as the configuration of FIG. 4.
The present invention improves upon the D-ring described above.